Dell XPS M1730 will not boot up. Black screen, lights turn on and harddrive is apparently functioning as the light for it functions. No sound including fans on either processor or GPU, no beeps when holding fx and powering on just lights. Light combination shows only that the computer is indeed receiving power. Any ideas? This is my 4th problem and nearly the entire laptop has already been replaced via extended warranty and the downtime is hurting my business.